Grain drier



1955 a. CAMPBELL 2,701,920

GRAIN DRIER Filed Aug. 18, 1952 2 Sheets-Sheet l ,Shwan I'm I (Ban ancampbzll W'itms! -9 t M Mama Arrow g5 B. CAMPBELL Feb. 15, 1955 GRAINDRIER 2 Sheets-Sheet 2 Fild Aug. 18, 1952 k/VAA A4\\AA MVAA BAAA M, AfAAA :{Bowan Campbell 4 Q0 ,fil'l'ornge' Witness M? United States PatentGRAIN DRIER Bowen Campbell, Des Moines, Iowa Application August 18,1952, Serial No. 304,920

10 Claims. (CI. 34-6 My invention relates to grain dryers and has forone of its objects the providing of a heated atr fan and a cooling airfan mounted on a single shaft and driven by a single motor.

Another object of this invention is to provide a dryer of the aboveclass in which the cooling area or portion thereof normally incommunication with the cooling air fan can be quickly and easily placedin communication with the heated air fan alone for drying a small batchof grain relative to the quantity for which the dryer is fully capableof.

Still another object of my grain dryers is to provide means foradjustably controlling the volume of air flow of both the cooling airand heated air fans.

A still further object of this invention is to provide in the graindrying portion of a dryer a plurality of obstacles in the flow path ofgrain that have a progressively increasing vertical spaced relationshipto each other whereby the depth of grain through which air is forced isgraduated for maximum drying efficiency and resulting quality.

Another object of my invention is to provide in grain dryers of theabove class a screen covered and shield protected air exhaust port thatis co-extensive with the height of the drying tower. In this respect theair exhaust openings are shielded from the weather and the screenelement eliminates condensation and icing.

These and other objects will be apparent to those skilled in the art. I

My invention consists in the construction, arrangement, and combinationof the various parts of the device, whereby the objects contemplated areattained as hereinafter more fully set forth, and specifically pointedout in my claims, and illustrated in the accompanying drawings, inwhich:

Fig. l is a perspective view of my dryer with a por- I tion of the towercut awayto more fully illustrate its construction,

fligg. 21 is a cross-sectional view taken on the line 2-2 0 1g.

Fig. 3 is an enlarged perspective view of a panel section used in thetower housing with a portion broken away to more fully illustrate itsconstruction in providing insulation,

Fig. 4 is an enlarged longitudinal section view of this dryer taken onthe line 44 of Fig. 1,

Fig. 5 is a schematic view of the dryer showing the cooling portion onlyfilled with grain and in communication with the source of heated air fora small batch drying, and

Fig. 6 is a schematic grain and illustrating the heated air.

Referring to the drawings I have used the numeral 10 to designate anenclosed frame support member arranged on a suitable supporting surfacesuch as the ground 12.- A tower housing 14 having a truncated shaped top16 is mounted on the support 10 as illustrated in Fig. 4. An inletconduit 18 in the top 16 communicates with the inside of the tower 14and is designed to extend to a source of grain supply for the filling ofthe tower therewith. At the bottom of the tower a funnel shaped portion20 extends into the enclosed frame 10 and communicates with a conveyer22 or any other suitable means for carrying the grain away. No inventionis claimed in the structure thus far deview of the dryer filled withflow of both the cooled and ice . 2 scribed as the elements recited andtheir relationship in general are common in the construction of graindryers.

The interior of the tower contains a plurality of baffle members 23 overand past which the gram flow in the drying process and for purposes ofidentification of the respective tower sides in describing the bafllearrangements and the drying elements I' have designated these sides bythe numerals 26, 28, 30 and 32 as shown more particularly in Fig. 2.Each'balfle 23 is in the form of an inverted V-shaped channel and aplurality are arranged in parallel spaced relationship to form ahorizontal row thereof that extends transversely of the longitudinalaxis of the tower. A plurality of such rows are arranged in verticalspaced relationship within the tower and in alternating rows thelongitudinal axes of all the baffle members in one reinvention withrespect to spective row are perpendicular to the longitudinal axes ofthe baffle members in the adjacent row, thus providing a criss-crossbaffle arrangement that thoroughly mixes the grain as it moves throughthe tower. It is pointed out in Fig. 4 that from the top of the towerdownwardly to point 34 is considered the drying portion of the tower andbelow point 34 is what is known as the cooling portion, and that in thedrying portion, the vertical spaced relationship between the rows ofbaffle members progressively increases from top to bottom. By thisarrangement, the depth of grain through which air is forced, as will belater described, is graduated for maximum efficiency and quality.

The inverted channel-like baffie members 23 are each open on each endand one series of alternate rows identified by the letter A in Fig. 2and as shown in Fig. 1 has the open ends extending between the towersides 28 and 32. The other series of alternating rows B likewise has itsends extending between the tower sides 26 and 30' and in each of therows A the respective ends of the bafiie member communicate with theoutside of the tower sides 28 and 32. The rows B each communicate withthe outside of the tower side 30 as illustrated in Figs. 1 and 2.

An air duct 36, progressively narrower from bottom to top, is formed byadding three sides to the tower -side 30 co-extensive with the height ofthe tower 14,

as shown in Fig. 1. Each side forming the duct, exclusive of the towerside 30, is formed from a plurality of individual panel members 38. Eachpanel 38 is of a double thickness with the inner and outer thicknessesspaced from each other and cross-broken so that there is an air spacetherebetween as shown in Fig. 3. This not only stiifens the panelconsiderably but when shiny aluminum is used, for example, an insulatingeffect is produced by the plurality of reflective surfaces.

Connected to the bottom of the duct 36 and frame 10 and resting on thesame plane as frame 10 is the fan housing 40 which also is connected onone side to a housing 42 on the same level which contains any suitableheat producing apparatus 44. A heating air fan 46 and a cooling air fan48 are positioned within the housing 40 and the rotors for each fan areon the same shaft 50 and driven by a single motor 52. The fans 46 and 48are separated by a vertical partition 54 that extends from the bottom ofhousing 40 toward but not to the top thereof as shown in Fig. 4. A stubpartition member 56 depends from the top of housing 40*in verticalalignment with partition 54 but is spaced therefrom and a movablebarrier 58 connected to a lever handle 60 on the outside of housing 40is adjustable as shown in Fig. 4 to open and close the space betweenpartitions 54 and 56. t The bottom portion of air duct 36 is dividedinto two air channels by means of a pat-tition formed from a pluralityof panels extending in endwise relationship as a continuation ofpartition 56 to point 34 on the tower (Fig. 4) which is the divisionpoint between the cooling and drying sections of the tower'as previouslydescribed. Thus, when the barrier member 58 is closed one air channel induct 36 communicates with the heating air fan 46 tocarry warm air to theupper or drying portion of the tower 14 as indicated by the arrows 62and the other air channel communicates with the cooling air fan 48 tocarry cool Patented Feb. 15, 1955 24 must air to, the lower or coolingportion of the tower, as illustrated by the arrows 64 in Fig. 4.

damper 66 in the housing 40 operated'by a lever 68 on the outside of thehousing is adapted to control the volume of heated air from the fan 46to the drying portion of the tower and a like damper 70 with controllever 72 is similarly used for the cooling air from fan 48 intended forthe cooling portion of the tower.

Fig. 6 illustrates the operation of this-dryer in what is known ascontinuous drying. Here grain 24 has entered the tower 14 through inlet18 and flows by gravity downwardly past the bathe members 23. At thesame time heat and cool air is blown into the respective drying andcooling sections through the openings in tower side 30 of the B seriesof bafiie rows as shown in Figs. 1 and 2. Eventually this warm and coolair will circulate under the battle members in rows A and B and leavethe tower through tower sides 28 and 32, as indicated by arrows 74 inFig. 2. -To protect the air exhaust ports in the tower sides 28 and 32from direct contact with the outside atmosphere, I provide therespective shield members 76 and 78 which extend from the respectiveends of tower side 30 to the respective points 80 and 82 in line withand spaced from the respective ends of tower side 26 as shown in Fig. 2.An exhaust screen member 84 is secured between the end of eachrespective shield 76 and 78 and the respective adjacent end thereto oftower side 26.

When the tower is initially filled with grain for a drying operation itis obvious that grain in the lower or cooling portion would not receivethe benefit of the heated air in the normal drying operation, and inthis regard, reference is-made to Fig. which illustrates the manner inwhich my dryer can be adapted to convert the cooling section thereofto-a drying section. For this purpose damper 70 is closed to cut offcool air from fan 48, damper 66 is closed to cut off warm air from theupper or normal drying portion of the tower and barrier 58 is opened sothat heated air blown by fan 46 will pass through the air channel whichnormally receives cool air. By this arrangement, shown in broken linesin Fig. 4, warm air is now furnished to the lower portion of the dryerfor a drying process. It is also pointed out that this last describedarrangement is usable also in drying only a small batch of grain. Itwill also be appreciated that the dampers 70 and 66 are adjustable sothat the air from the fans may be used to best advantage in the dryingof light weight grains such as oats, flax, etc., and this is materialsince a full volume of air needed for heavier grains could blow thelighter ones out of the tower. Also, the air volume control by means ofthese dampers is advantageous in very cold weather when little coolingis necessary. It will be observed that when outdoor humidity is high,the cooling air quite often puts moisture into the grain in cooling itand therefore in winter, for

example, when the relative humidity of air is usually rather high andnot much cooling air is necessary, it is a decided advantage to reduceair volume to prevent adding any more moisture than necessary in thecooling process.

Some changes may be made in the construction and arrangement of my graindryer without departing from the real spirit and purpose of myinvention, and it is my intention to cover by my claims, any modifiedforms of structure or use of mechanical equivalents which may bereasonably included within their scope.

I claim:

1. In a grain dryer, a tower having an inlet port and an outlet port,means for supporting said dryer, a housing arranged adjacent said towersupporting means, an air duct co-extensive in height with and mounted onsaid tower and having its bottom end in communication with said housing,said air duct also in communication with the tower interior, a partitionin the lower portion of said air duct to divide the same into twochannels, one of which communicates with the lower portion of'the toweronly and the other communicating only with the upper portion of thetower, a partition in said housing dividing the same into twocompartments, one of which communicates through one of said channels tothe upper portion of said tower and the other communicates through theother channel with thelower portion of said tower, a movable barrier insaid last mentioned partition whereby said compartments can be incommunication with each other, a shaft rotatably mounted in said housingso that a portion thereof extends into each of said compartments, meansfor rotating said shaft, two fans in said housing each in onecompartment'respectively and having their rotors mounted on said shaft,one fan being a cool air fan in communication with the outsideatmosphere and the other a heated air fan in communication with a sourceof heated air, the cool air fan furnishing cool air to the lower portionof the tower and the heated air fan normally furnishing heated air tothe upper portion of the tower, a damper in each compartment forcontrolling or closing off the volume of air from the cool air andheated air fans to the lower and upper tower portions respectively, andwhen each of said dampers is closed and said movable barrier is opened,said heated air fan can furnish warm air to the lower portion of saidtower only.

2. In a grain dryer, a rectangular tower having a grain inlet port andgrain outlet port, a series of horizontal vertically spaced apart rowsof inverted V-shaped Open end elongated bathe members in said tower, thelongitudinal axes of each bathe in each respective row being parallel toeach other and the rows arranged so that in alternate rows thelongitudinal axes of the battles in respective rows are perpendicular toeach other to form a network of criss-cross bafiies through which thegrain must pass, an open end of each bafile in one alternate series ofrows each communicating with the outside of one tower side to provideair exhaust openings, and one open end of each bafile in the otherseries of alternate rows communicating with the outside of another sideof the tower to provide an air inlet opening, an air duct mounted onsaid tower and in communication with each of said air inlet openings, apartition in the lower portion of said air duct to divide the same intotwo channels, one of which communicates with the lower portion of thetower only and the other communicating only with the upper portion ofthe tower, a housing connected to and communicating with said air ductat the bottom thereof, a shaft rotatably mounted in said housing, meansfor rotating said shaft, two fans in said housing each having theirrotors mounted on said shaft, one of said fans communicating with coolair from the atmosphere and the other communicating with a source ofheated air, one fan propelling heated air to the upper portion of thetower and the other furnishing cool air to the lower portion of thetower.

3. In a grain dryer, a rectangular tower having a grain inlet port and.grain outlet port, a series of horizontal vertically spaced apart rowsof inverted V-shaped open end elongated bafile members in said tower,the longitudinal axes of each bathe in each respective row beingparallel to each other and the rows arranged so that in alternate rowsthe longitudinal axes of the baffies in respective rows areperpendicular to each other to form a network of criss-cross baffiesthrough which the grain must pass, an open end of each bathe in onealternate series of rows each communicating with the outside of onetower side to provide air exhaust openings, and one open end of eachbathe in the other series of alternate rows communicating with theoutside of another side of the .tower to provide an air inlet opening,an air duct mounted on said tower and in communication with each of saidair inlet openings, a partition in the lower portion of said air duct todivide the same into two channels, one of which communicates with thelower portion of the tower only and the other communicating only withthe upper portion of the tower, a partition in said housing dividing thesame into two compartments, one of which communicates through one ofsaid channels to the upper portion of said tower and the othercommunicates through the other channel with the lower portion of saidtower, a movable barrier in said last mentioned partition whereby said'compartments can be in communication with each other, a shaft rotatablymounted in said housing so that a portion thereof extends into each ofsaid compartments, means for rotating said shaft, two fans in saidhousing each in one compartment respectively and having their rotorsmounted on said shaft, one fan being a cool air fan in communicationwith the outside atmosphere and the other a heated air fan incommunication with a source of heated air, the cool air fan furnishingcool air to the lower portion of the tower and the heated air fannormally furnishing heated air to the upper portion of the tower, adamper in each compartment for controlling or closing oil? the volume ofair from the cool air and heated air fans to the lower and upper towerportions respectively, and when each of said dampers is closed and saidmovable barrier is opened, said heated air fan can furnish warm air tothe lower portion of 4 said tower only. s

4. A device as defined in claim 3 characterized by a shield membersecured to said tower and extending outwardly' across and spaced fromsaid air exhaust openings. 5. In a grain dryer, a tower having an inletport and an outlet port, means for supporting said dryer, a housingarranged adjacent said tower supporting means, an air duct coextensivein height with and mounted on said tower and having its bottom end incommunication with said housing, said air duct also in communicationwith the tower interior, a partition in the lower portion of said airduct to divide the same into two channels, one of which communicateswith the lower portion of the tower only and the other communicatingonly with the upper portion of the tower, a shaft rotatably mounted insaid housing, means for rotating said shaft, twofans in said housingeach having their rotors mounted on said shaft, one of said fanscommunicating with cool air from the atmosphere and the othercommunicating with a source of heated air, one fan propelling heated airto the upper portion of the tower and the other furnishing cool air tothe lower portion of the tower, and means in said housing closing offcool air to the lower portion of the tower and heated air to the upperportion thereof and directing the heated air to the lower portion onlyof said tower. I

6. In a grain dryer, a tower having an inlet port and an outlet port, ahousing adjacent said tower, an air duct mounted on said tower and incommunication with said housing, said air duct also in communicationwith the tower interior, a partition in said air duct to divide the sameinto two channels, one of which communicates with the lower portion ofthe tower only and the other communicating only with the upper portionof the tower, a shaft rotatably mounted in said housing, means forrotating said shaft, two fans in said housing each having their rotorsmounted on said shaft, one of said fans communicating with cool air fromthe atmosphere and the other communicating with a source of heated air,one fan propelling heated air to the upper portion of the tower and theother furnishing cool air to the lower portion of the tower, and meansin said housing closing off cool air to the lower portion of the towerand heated air to the upper portion thereof and directing the heated airto the lower portion only of said tower.

7. In a grain dryer, a tower having an inlet port and an outlet port,means for supporting said dryer, a housing arranged adjacent said towersupporting means, an air duct coextensive in height with and mounted onsaid tower and having its bottom end in communication with said housing,said air duct also in communication with the tower interior, a partitionin the lower portion of said air duct to divide the same into twochannels, one of which communicates with the lower portion of the toweronly and the other communicating only with the upper portion of thetower, two fans in said housing, means for operating the same, one ofsaid fans communicating with cool air from the atmosphere and the othercommunicating with a source of heated air, one fan propelling heated airto the upper portion of the tower and the other furnishing cool air tothe lower portion of the tower, and means in said housing closing offcool air to the lower portion of the tower and heated air to the upperportion thereof and directing the heated air to the lower portion onlyof said tower.

8. In a grain dryer, a tower having an inlet port and an outlet port, ahousing adjacent said tower, an air duct mounted on said tower and incommunication with said housing, said air duct also in communicationwith the tower interior, a partition in said air duct to divide the sameinto two channels, one of which communicates with the lower portion ofthe tower only and the other communicating only with the upper portionof the tower, two fans in said housing, means for operating the same,

one of said fans communicating with cool atr from the atmosphere and theother communicating with a source of heated air, one fan propellingheated air to the upper portion of the tower and the other furnishingcool air to the lower portion of the tower, and means in said housingclosing off cool air to the lower portion of the tower and heated air tothe upper portion thereof and directing the heated air to the lowerportion only of said tower.

9. In a grain dryer, a tower having an inlet port and an outlet port, ahousing adjacent said tower, an air duct mounted on said tower and incommunication with said housing, said air duct also in communicationwith the tower interior, a partition in said air duct to divide the sameinto two channels, one of which communicates with the lower portion ofthe tower only and the other communicating only with the upper'portionof the tower, a partition in said housing dividing the same into twocompartments, one of which communicates through one of said channels tothe upper portion of said tower and the other communicates through theother channel with the lower portion of said tower, a movable barrier insaid last mentioned partition whereby said compartments can be incommunication with each other, two fans in said housing each in onecompartment respectively, means for operating said fans, one fan being acool air fan in communication with the outside atmosphere and the othera heated air fan in communication with a source of heated air, the coolair fan furnishing cool air to the lower portion of the tower and theheated air fan normally furnishing heated air to the upper portion ofthe tower, a damper in each compartment for controlling or closing offthe volume of air from the cool air and heated air fans to the lower andupper tower portions respectively, and when each of said dampers isclosed and said movable barrier is opened, said heated air fan canfurnish warm air to the lower portion of said tower only.

10. In a grain dryer, a rectangular tower having a grain inlet port andgrain outlet port, a series of horizontal vertically spaced apart rowsof inverted V-shaped open end elongated bafile members in said tower,the longitudinal axes of each bathe in each respective row beingparallel to each other and the rows arranged so that in alternate rowsthe longitudinal axes of the baflles in respective rows areperpendicular to each other to form a network of criss-cross bafilesthrough which the grain must pass, an open end of each baffle in onealternate series of rows each communicating with the outside of onetower side to provide air exhaust openings, and one open end of eachbathe in the other series of alternate rows communicating with theoutside of another side of the tower to provide an air inlet opening, anair duct mounted on said tower and in communication with each of saidair inlet openings, a partition in said air duct to divide the same intotwo channels, one of which communicates with the lower portion of thetower only and the other communicating only with the upper portion ofthe tower, a housing communicating with said air duct, two fans in saidhousing, means for operating said fans, one of said fans communicatingwith cool air from the atmosphere and the other communicating with asource of heated air, one fan propelling heated air to the upper portionof the tower and the other furnishing cool air to the lower portion ofthe tower, and means in said housing closing off cool air to the lowerportion of the tower and heated air to the upper portion thereof anddirecting the heated airto the lower portion only of said tower.

References Cited the file of this patent V UNITED STATES PATENTS

